Ranking of Modifiable Lifestyle Risk Factors for Breast Cancer in Saudi Women: Population Attributable Risk and Nomogram.

Purpose: Breast cancer is the most common cancer among women in the Saudi Arabia, and over 50% of the cases are detected at a late stage. This study aimed to estimate population attributable risk percentage (PAR%) of modifiable lifestyle risk factors for breast cancer in Saudi Arabia.

Patients and methods: A secondary analysis of previously published papers was performed . Relative risks (RR) and odds ratios (OR) were obtained from published international epidemiological studies, and the prevalence of each risk factor in Saudi Arabia was obtained from various sources (eg, national surveys and published literature) to calculate PAR%. A nomogram was used to visually translate the RRs/ORs and their prevalence into PAR% using a practical tool.

Results: Seven modifiable lifestyle risk factors for breast cancer were identified in Saudi Arabia. The identified risk factors included lack of physical activity (sedentary lifestyle), oral contraception (current use), obesity (postmenopausal), hormone replacement therapy (current use), passive smoking, age at first birth (≥ 35 years), and tobacco smoking (current or daily smoking). The PAR% for these risk factors ranged from 0.5% for tobacco smoking to 23.1% for a lack of physical activity. Few modifiable lifestyle risk factors were excluded from this study, due to limited nor unavailable data in Saudi Arabia (eg, alcohol consumption, breastfeeding patterns and childbearing patterns, obesity according to menopausal status, and night-shift work).

Conclusion: Physical inactivity has the most significant modifiable health impact and is a major risk factor for breast cancer. Removing this risk factor would reduce the prevalence of breast cancer in the Saudi population by 23%. There is an immense need to prioritize cancer control strategies based on local needs, current data on cancer risk factors, and the disease burden.